package org.appenders.log4j2.elasticsearch;

/*-
 * #%L
 * log4j2-elasticsearch
 * %%
 * Copyright (C) 2022 Rafal Foltynski
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

import java.time.Instant;
import java.time.format.DateTimeFormatter;

public final class DateTimeFormatterWrapper implements MillisFormatter {

    private final DateTimeFormatter formatter;
    private final int bufferSize;

    protected DateTimeFormatterWrapper(final DateTimeFormatter formatter,
                                       final int bufferSize) {
        this.formatter = formatter;
        this.bufferSize = bufferSize;
    }

    @Override
    public String format(final long millis) {
        final StringBuilder buffer = new StringBuilder(bufferSize);
        formatter.formatTo(Instant.ofEpochMilli(millis), buffer);
        return buffer.toString();
    }

}
